Question

Giải các phương trình sau :

a) \(\left(4x-10\right)\left(24+5x\right)=0\)

b) \(\left(3,5-7x\right)\left(0,1x+2,3\right)=0\)

c) \(\left(3x-2\right)\left(\dfrac{2\left(x+3\right)}{7}-\dfrac{4x-3}{5}\right)=0\)

d) \(\left(3,3-11x\right)\left(\dfrac{7x+2}{5}+\dfrac{2\left(1-3x\right)}{3}\right)=0\)

Answer 1

a) \(\left(4x-10\right)\left(24+5x\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}4x-10=0\\24+5x=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{10}{4}=\dfrac{5}{2}\\x=-\dfrac{24}{5}\end{matrix}\right.\)

Vậy \(S=\left\{-\dfrac{24}{5};\dfrac{5}{2}\right\}\)

b) \(\left(3.5-7x\right)\left(0.1x+2.3\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}3.5-7x=0\\0.1x+2.3=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{3.5}{7}=\dfrac{1}{2}\\x=-\dfrac{2.3}{0.1}=-23\end{matrix}\right.\)

Vậy \(S=\left\{-23;\dfrac{1}{2}\right\}\)